Search results for "platinum"

Influence of metallic silver and of platinum-silver bimetallic deposits on the photocatalytic activity of titania (anatase and rutile) in organic and…

1998

Abstract The influence of deposited silver upon the photocatalytic activity of titania in the rutile and anatase allotropic forms has been studied in three different reactions. The common feature found for these three reactions was an electron transfer from illuminated TiO 2 to silver particles. In the first reaction (platinum photodeposition). it has been shown that the initial presence of metallic silver orientates the localization of subsequent Pt photodeposits with, in particular, a 100% selectivity to Pt deposition on top of silver particles or agglomerates previously deposited on anatase. In the second reaction (2-propanol oxidation), Ag deposit was found beneficial for the activity o…

Nanostructured Pt–TiO2 composite thin films obtained by direct liquid injection metal organic chemical vapor deposition: Control of chemical state by…

2015

Abstract Nanostructured Pt–TiO 2 composite thin films were synthesized by direct liquid injection metal organic chemical vapor deposition process, using trimethyl(methylcyclopentadienyl)platinum and titanium isopropoxide as precursors. Surface and cross-sectional morphologies obtained by scanning electron microscopy and transmission electron microscopy evidenced the uniform distribution of platinum nanoparticles in the TiO 2 matrix. At higher Pt content, the X-ray diffraction analysis showed that the face-centered cubic phase of platinum appeared together with an anatase TiO 2 structure. In addition, as far as the platinum chemical state is concerned, the co-deposition of TiO 2 and Pt allow…

Reactions of platinum(iv)-bound nitriles with isomeric nitroanilines: addition vs. substitution

2012

The platinum(IV) complex trans-[PtCl(4)(EtCN)(2)] reacts smoothly and under mild conditions with isomeric o-, m- and p-nitroanilines (NAs) yielding two different types of products depending on the NA isomer, viz. the nitroaniline complexes cis/trans-[PtCl(4)(NA)(2)] (cis/trans-1-3) and the amidine species trans-[PtCl(4){NH=C(Et)NHC(6)H(4)NO(2)-m}(EtCN)] (4), trans-[PtCl(4){NH=C(Et)NHC(6)H(4)NO(2)-m}(2)] (5) and trans-[PtCl(4){NH=C(Et)NHC(6)H(4)NO(2)-p}(EtCN)] (6). Complexes 4 and 5 undergo cyclometalation, furnishing mer-[PtCl(3){NH=C(Et)NHC(6)H(3)NO(2)-m}(EtCN)] (7) and mer-[PtCl(3){NH=C(Et)NHC(6)H(4)NO(2)-m}{NH=C(Et)NHC(6)H(3)NO(2)-m}] (8), respectively. Moreover, 8 both in the solid stat…

Chemotherapy and immunomodulation: from immunogenic chemotherapies to novel therapeutic strategies.

2013

Study of Redox Processes in Zeolite Y-Associated 2,4,6-Triphenylthiopyrylium Ion by Square Wave Voltammetry

2003

The electrochemical responses of 2,4,6-triphenylthiopyrylium ion (TTP+) in solution and attached to zeolite Y (TTP@Y) are described using cyclic and square wave voltammetries upon immersion of zeolite-modified polymer film electrodes in MeCN (LiClO4, Et4NClO4, and BuN4PF6 electrolytes) and aqueous (LiNO3, NaNO3, and KNO3 electrolytes) media. The electrochemistry of TTP@Y in contact with Bu4NPF6/MeCN is identical to that of TTP(BF4) in solution, with reduction processes at −0.25, −0.74, and −1.36 V vs SCE, and oxidation steps at +0.85 and +1.11 V. This response differs from those obtained for TTP@Y in Et4NClO4/MeCN and LiClO4/MeCN electrolytes. In contact with aqueous electrolytes, TTP@Y dis…

Primary endpoint results of the OMEGA Study: One-year clinical outcomes after implantation of a novel platinum chromium bare metal stent.

2014

Bare metal stents (BMS) have similar rates of death and myocardial infarction (MI) compared to drug-eluting stents (DES). DES lower repeat revascularization rates compared to BMS, but may have higher rates of late stent thrombosis (ST) potentially due to impaired endothelialization requiring longer dual anti-platelet therapy (DAPT). OMEGA evaluated a novel BMS designed to have improved deliverability and radiopacity, in comparison to currently available platforms.OMEGA was a prospective, multicenter, single-arm study enrolling 328 patients at 37 sites (US and Europe). Patients received the OMEGA stent (bare platinum chromium element stent) for the treatment of de novo native coronary artery…

A study of the behaviour of Pt supported on CeO2–ZrO2/Al2O3–BaO as NO storage–reduction catalyst for the treatment of lean burn engine emissions

2002

Abstract The behaviour of a Pt(1 wt.%) supported on CeO2–ZrO2(20 wt.%)/Al2O3(64 wt.%)–BaO(16 wt.%) as a novel NOx storage–reduction catalyst is studied by reactivity tests and DRIFT experiments and compared with that of Pt(1%)–BaO(15 wt.%) on alumina. The former catalyst, designed as a hydrothermally stable sample, is composed of an alumina modified with Ba ions and an overlayer of ceria-zirconia. The results pointed out that during the calcination barium ions migrates over the surface of the catalyst which thus show a good NOx storage–reduction behaviour comparable with that of Pt–BaO on alumina, although Ba ions result much better dispersed.

Über die struktur aus 2,4,6-tri(dihydroxymethyl-amino)-1,3,5-triazin (hexamethylolmelamin) erhaltener polykondensate

1960

Die Polykondensation von Hexamethylolmelamin bei 110°C bis 150°C in Platintiegeln und im Stickstoffstrom erfolgt ohne ein Schmelzen der weisen, pulverigen Proben. Es wird hierbei der Gewichtsverlust, sowie quantitativ der abgespaltene Formaldehyd und das abgespaltene Wasser bestimmt. Aus den Elementaranalysen der Polykondensate einerseits, sowie dem Gewichtsverlust und den Spaltprodukten andererseits, lassen sich fur den durchschnittlichen Grundbaustein der Polykondensate innerhalb einer gewissen Streuung ubereinstimmende Summenformeln ableiten. Aus den Summenformeln und dem quantitativ verfolgten Polykondensationsverlauf schlieslich ergeben sich die Konstitutionsformeln der durchschnittlic…

Reactivity of anticancer metallodrugs with serum proteins: New insights from size exclusion chromatography-ICP-MS and ESI-MS

2010

International audience; A method based on the coupling of high resolution size-exclusion liquid chromatography using a polymer stationary phase with inductively coupled plasma mass spectrometry was developed to study the interactions of two metallodrugs - cisplatin and RAPTA-T - with the serum proteins albumin and transferrin. In contrast to previous approaches, the technique allowed the total recovery of the metals from the column and was able to discriminate between the different species of the metallodrugs and their complexes with the proteins at femtomolar detection levels. Metal binding was found to be dependent on the protein concentration and on the incubation time of the sample. Cis…

Spectroscopic study of the loading of cationic porphyrins by carbon nanohorns as high capacity carriers of photoactive molecules to cells

2019

Carbon nanomaterials are attractive candidates for drug delivery due to their high surface area, ease of functionalisation and biocompatibility. This work describes the spectroscopic monitoring of the loading capacity of oxidised carbon nanohorns for two cationic porphyrins. Addition of the COOH functionalised carbon nanohorns to both meso-tetra(4-N-methylpyridyl) free base (H2TMPyP4) and platinum (PtTMPyP4) porphyrin in aqueous solution results in hypochromism of the Soret band and quenching of the porphyrin emission. These changes are used to monitor the non-covalent binding interactions with the nanohorn surface and determine the surface loading. The colloidal stability of the nanohorns …